It also has experimental support for Cisco's VLAN Query Protocol
(VMPS) and DHCP.

Please read the DEBUGGING section below. It contains instructions
for quickly configuring the server for your local system.

OPTIONS

The following command-line options are accepted by the server.

-C

Check the configuration and exit immediately. If there is a problem
reading the configuration, then the server will exit with a non-zero
status code. If the configuration appears to be acceptable, then the
server will exit with a zero status code.

Note that there are many limitations to this check. Due to the
complexities involved in almost starting a RADIUS server, these
checks are necessarily incomplete. The server can return a zero
status code when run with -C, but may still exit with an error when
run normally.

See the output of
radiusd -XC
for an informative list of which modules are checked for correct
configuration, and which modules are skipped, and therefore not checked.

-d config directory

Defaults to /etc/raddb. Radiusd looks here for its configuration
files such as the dictionary and the users files.

-i ip-address

Defines which IP address that the server uses for sending and
receiving packets.

If this command-line option is given, then the "bind_address" and all
"listen{}" entries in radiusd.conf are ignored.

This option MUST be used in conjunction with "-p".

-f

Do not fork, stay running as a foreground process.

-n name

Read raddb/name.conf instead of raddb/radiusd.conf.

-p port

Normally radiusd listens on the ports specified in /etc/services
(radius and radacct). When this option is given, radiusd listens on
the specified port for authentication requests and on the specified
port +1 for accounting requests.

If this command-line option is given, then the "port" directive in
radiusd.conf is ignored.

This option MUST be used in conjunction with "-i".

-s

Run in "single server" mode. The server normally runs with multiple
threads and/or processes, which can lower its response time to
requests. Some systems have issues with threading, however, so
running in "single server" mode may help to address those issues. In
single server mode, the server will also not "daemonize"
(auto-background) itself.

-v

Print server version information and exit.

-X

Debugging mode. Equivalent to "-sfxx -l stdout". When trying to
understand how the server works, ALWAYS run it with "radiusd -X".

-x

Finer-grained debug mode. In this mode the server will print details
of every request on it's stdout output. You can specify this
option multiple times (-x -x or -xx) to get more detailed output.

DEBUGGING

The server can be difficult to configure correctly in systems with
complex requirements. We STRONGLY RECOMMEND proceeding via the
following steps:

1) Always run the server in debugging mode (
radiusd -X
). We cannot emphasize this enough. If you are not running the
server in debugging mode, you will not be able to see what is
doing, and you will not be able to correct any problems.

2) Change as little as possible in the default configuration files.
The server contains a decade of experience with protocols, databases,
and different systems. Its default configuration is designed to work
almost everywhere, and to do almost everything.

3) Make small changes to the configuration files, while testing each
change as you make it. If the change works, save a copy of the
configuration, and make another change. If the change doesn't work,
debug it, and try to understand why it doesn't work.

If you begin by making large changes to the server configuration, it
will never work, and you will never be able to debug it.

4) If you need to add a connection to a database FOO (e.g. LDAP or
SQL), then:

a) Edit raddb/modules/foo
This file contains the default configuration for the module. It
contains comments describing what can be configured, and what those
configuration entries mean.

b) Edit raddb/sites-available/default
This file contains the default policy for the server. e.g. "enable
CHAP, MS-CHAP, and EAP authentication". Look in this file for all
references to your module "foo". Read the comments, and remove the
leading hash '#' from the lines referencing the module. This enables
the module.

c) Edit raddb/sites-available/inner-tunnel
This file contains the default policy for the "tunneled" portion of
certain EAP methods. Perform the same kind of edits as above, for the
"default" file.. If you are not using EAP (802.1X), then this step
can be skipped.

5) Ask questions on the mailing list
(freeradius-users@lists.freeradius.org). When asking questions,
include the output from debugging mode (
radiusd -X
). This information will allow people to help you. If you do not
include it, the first response to your message will be "post the
output of debug mode".

Ask questions earlier, rather than later. If you cannot solve a
problem in a day, ask a question on the mailing list. Most questions
have been seen before, and can be answered quickly.

BACKGROUND

RADIUS is a protocol spoken between an access server, typically
a device connected to several modems or ISDN lines, and a radius
server. When a user connects to the access server, (s)he is asked for
a loginname and a password. This information is then sent to the radius
server. The server replies with "access denied", or "access OK". In the
latter case login information is sent along, such as the IP address in
the case of a PPP connection.

The access server also sends login and logout records to the radius
server so accounting can be done. These records are kept for each terminal
server seperately in a file called detail, and in the wtmp
compatible logfile /var/log/radwtmp.

CONFIGURATION

Radiusd uses a number of configuration files. Each file has it's
own manpage describing the format of the file. These files are:

radiusd.conf

The main configuration file, which sets the administrator-controlled
items.

dictionary

This file is usually static. It defines all the possible RADIUS attributes
used in the other configuration files. You don't have to modify it.
It includes other dictionary files in the same directory.

hints

Defines certain hints to the radius server based on the users's loginname
or other attributes sent by the access server. It also provides for
mapping user names (such as Pusername -> username). This provides the
functionality that the Livingston 2.0 server has as "Prefix" and
"Suffix" support in the users file, but is more general. Ofcourse
the Livingston way of doing things is also supported, and you can even use
both at the same time (within certain limits).

huntgroups

Defines the huntgroups that you have, and makes it possible to restrict
access to certain huntgroups to certain (groups of) users.

users

Here the users are defined. On a typical setup, this file mainly contains
DEFAULT entries to process the different types of logins, based on hints
from the hints file. Authentication is then based on the contents of
the UNIX /etc/passwd file. However it is also possible to define all
users, and their passwords, in this file.